CVD法制备p-ZnO薄膜/n-Si异质结发光二极管及其性能研究

利用简单的化学气相沉积方法, 首先在n-Si衬底上生长Sb掺杂p-ZnO薄膜, 并在此基础上制作了p-ZnO/n-Si异质结发光二极管．对制备的Sb掺杂ZnO薄膜 在800 ℃下进行了热退火处理, 发现退火后样品的晶体质量和表面形貌都得到明显提高, 并且薄膜呈现的电导类型为p型, 载流子浓度为9.56× 10¹⁷ cm^-3. 此外, 该器件还表现出良好的整流特性, 正向开启电压为4.0 V, 反向击穿电压为9.5 V. 在正向45 mA的注入电流条件下, 器件实现了室温下的电致发光. 这说明较高质量的ZnO薄膜也可以通过简单的化学气相沉积方法来实现, 这为ZnO基光电器件的材料制备提供了一种简单可行的方法. 关键词： CVD p-ZnO 异质结 电致发光     

氧离子注入微晶金刚石薄膜的微结构与光电性能研究

本文系统研究了氧离子注入剂量和退火温度对含有Si-V发光中 心的微晶金刚石薄膜的微结构和光电性能的影响. 结果表明, 氧离子注入并在较高温度退火有利于提高薄膜中Si-V中心的发光强度. 当氧离子注入剂量从10¹⁴ cm^-2增加到10¹⁵ cm^-2时, 薄膜中Si-V发光强度增强. Hall效应测试结果表明退火后薄膜的面电阻率降低. 不同温度退火时, 氧离子注入薄膜的Si-V发光强度较强时, 薄膜的面电阻率增加, 说明Si-V发光中心不利于提高薄膜的导电性能. Raman光谱测试结果表明, 薄膜中缺陷数量的增多会增强Si-V的发光强度, 而降低薄膜的导电性能. 关键词： 金刚石薄膜 氧离子注入 电学性能 Si-V缺陷     

溶胶-凝胶法制备Li-N双掺p型ZnO薄膜的结构、光学和电学性能

采用溶胶-凝胶法在n型Si(100)衬底上沉积Li-N双掺杂ZnO薄膜,经X射线衍射和扫描电镜图片分析,所制备薄膜具有多晶纤锌矿结构和高的c轴择优取向.室温下霍尔效应测试结果显示Li-N双掺杂ZnO薄膜具有p型导电特性.在Li掺杂量为15.0at%,Li/N（摩尔比）为1∶1,700℃退火等优化条件下得到的最佳电学性能结果是：电阻率为0.34 Ω·cm,霍尔迁移率为16.43 cm²/V·s,载流子浓度为2.79×10¹⁹ cm^{-3关键词： Li-N双掺 p型ZnO薄膜 溶胶-凝胶 性能}     

C60薄膜的离子注入损伤研究

在200 keV重离子加速器上，用120—360 keV的H,N,Ar和Mo离子注入C₆₀薄膜．对注入后薄膜的拉曼谱进行了分析．结果表明，不同离子注入C₆₀薄膜后，C₆₀的1469 cm^-1特征峰随注入剂量的增加均呈指数式下降，同时在1300—1700 cm^-1范围出现非晶碳峰，并逐渐增强，最终完全非晶化．而且1469 cm^-1拉曼峰的强度及C₆₀薄膜完全非晶化所对应的剂量与注入离子的种类和能量有关．进一步的分析表明，C₆₀分子的损伤主要是由注入离子的核能量转移所造成，与电子能量转移无关．H离子注入C₆₀薄膜后，1469 cm^-1处特征拉曼峰向短波方向非对称展宽，这可能是注入的H离子通过电子能量转移使C₆₀分子发生聚合的结果. 关键词：     

N2流量对N掺杂MgZnO薄膜结构和性能的影响

利用射频磁控溅射方法,使用Mg_{0. 04}Zn_0.96O 陶瓷靶材,选用不同流量比的氮气和氩气混和气体作为溅射气体,在石英基片上生长N掺杂Mg_xZn_1-xO合金薄膜。研究了氮流量比对薄膜组分、结构、形貌、电学性质和拉曼光谱的影响。结果显示：随着溅射气氛中氮流量比的增加,薄膜中Mg含量增加,薄膜表面颗粒尺寸减小,结晶质量变差,电阻率逐渐增大,导电类型发生转变。在氮流量比为20%时,获得了最好的p型导电薄膜。另外,随着氮流量比的增加,拉曼光谱中与N_O相关的位于272 cm^-1、642 cm^-1左右的振动峰逐渐增强,表明N_O的浓度随着氮流量比的加大而有所增加。     

基于离子注入技术的ZnMnO半导体材料的制备及光谱表征

通过离子注入技术制备了ZnMnO半导体材料，研究离子注入剂量与退火对材料光谱性质的影 响.Raman光谱研究发现，575cm^-1处声子模展宽是由高剂量Mn注入引起的缺陷所 致，退火样品528cm^-1振动模来自Mn相关的杂质振动.室温光致发光谱表明，退 火对高剂量注入样品的可见发光带有增强作用. 关键词： ZnMnO 离子注入 Raman光谱 室温光致发光     

通过交替生长气氛调控N掺杂ZnO薄膜电学特性

使用分子束外延方法在c面蓝宝石衬底上生长了系列氮掺杂ZnO薄膜样品。在连续的富锌气氛环境中生长的样品,由于存在大量的施主缺陷,呈现n型电导。为了抑制施主缺陷带来的补偿效应,在生长过程中,通过周期性补充氧气,形成周期性的富氧气氛,缓解了氮掺杂浓度和施主缺陷浓度之间的矛盾。光致发光测量表明,通过交替生长气氛,氧空位和锌间隙等缺陷在薄膜中得到了显著抑制。通过交替生长气氛生长的外延薄膜的结晶质量也有所提高。样品显示出重复性较高的p型电导,载流子浓度可达到10¹⁶ cm^-3。周期性补氧调节生长气氛的生长方式是一种有效实现p型掺杂ZnO的方法。     

p型ZnO薄膜的制备及特性

采用射频磁控溅射在Si片上制备ZnO薄膜，通过离子注入对样品进行N掺杂，在不同温度下进行退火并实现了p型转变.用扫描电子显微镜、X射线衍射和Hall测量对薄膜进行了表征，结果表明薄膜具有良好的表面形貌和高度c轴择优取向，退火后p型ZnO薄膜的最高载流子浓度和最低电阻率分别为1.68×10¹⁶cm^-3和41.5Ω·cm.讨论并分析了退火温度和时间对ZnO薄膜p型转变的影响.     

Ti离子注入和退火对ZnS薄膜结构和光学性质的影响

利用真空蒸发法在石英玻璃衬底上制备了ZnS薄膜,将能量80 keV,剂量1×10¹⁷ cm^-2的Ti离子注入到薄膜中,并将注入后的ZnS薄膜进行退火处理,退火温度500—700 ℃.利用X射线衍射（XRD）研究了薄膜结构的变化,利用光致发光（PL）和光吸收研究了薄膜光学性质的变化.XRD结果显示,衍射峰在500 ℃退火1 h后有一定程度的恢复;光吸收结果显示,离子注入后光吸收增强,随着退火温度的上升,光吸收逐渐降低,吸收边随着退火温度的提高发生蓝移;PL显示,薄 关键词： ZnS薄膜 离子注入 X射线衍射 光致发光     

Al和Sb共掺对ZnO有序阵列薄膜的结构和光学性能的影响

采用水热合成法在预先生长的ZnO种子层的玻璃衬底上制备出Al和Sb共掺ZnO纳米棒有序阵列薄膜. 通过X射线衍射、扫描电镜、透射电镜和选区电子衍射分析表明:所制备的薄膜由垂直于ZnO种子层的纳米棒组成, 呈单晶六角纤锌矿ZnO结构, 且沿[001]方向择优生长, 纳米棒的平均直径和长度分别为27.8 nm和1.02 μm. Al和Sb共掺ZnO纳米棒有序阵列薄膜的拉曼散射分析表明:相对于未掺杂ZnO薄膜的拉曼振动峰(580 cm^-1), Al和Sb共掺ZnO阵列薄膜的E₁(LO)振动模式存在拉曼位移. 当Al和Sb的掺杂量为3.0at%,4.0at%,5.0at%,6.0at%时, Al和Sb共掺ZnO阵列薄膜的拉曼振动峰的位移量分别为3,10,14,12 cm^-1. E₁ (LO) 振动模式位移是由Al和Sb掺杂ZnO产生的缺陷引起的. 室温光致发光结果表明:掺杂Al和Sb后, ZnO薄膜在545 nm处的发光强度减小,在414 nm处的发光强度增加. 这是由于掺杂Al和Sb后, ZnO薄膜中Zn_i缺陷增加, O_i缺陷减少引起的. 关键词： Al和Sb共掺ZnO薄膜 纳米棒有序阵列 结构表征 拉曼散射     

The microstructures and the electrical and optical properties of ZnO:N films prepared by thermal oxidation of Zn3N2 precursor

Samples of p-type ZnO:N films were prepared on glass substrates by thermal oxidation of Zn₃N₂ precursor, which was produced by reactive magnetron sputtering with a metallic zinc target in Ar/N₂ working gas. The microstructures and the electrical and optical properties of the samples were systematically investigated as a function of the annealing temperature. The results indicate that the annealing temperature has strong effects on the conductivity and photoluminescence (PL) properties of the obtained ZnO:N films. With an annealing temperature of 500 ^°C in oxygen flux, ZnO:N samples show the best p-type characteristics. The doping mechanism and the doping efficiency are briefly discussed based on the experimental results.     

Improvement of electrical and optical properties of Ga and N co-doped p-type ZnO thin films with thermal treatment

Ga and N co-doped p-type ZnO thin films were epitaxially grown on sapphire substrate using magnetron sputtering technique. The process of synthesized Ga and N co-doped ZnO films was performed in ambient gas of N₂O. Hall measurement shows a significant improvement of p-type characteristics with rapid thermal annealing (RTA) process in N₂ gas flow, where more N acceptors are activated. The film rapid thermal annealed at 900 °C in N₂ ambient revealed the highest carrier concentration of 9.36 × 10¹⁹ cm⁻³ and lowest resistivity of 1.39 × 10⁻¹ Ω cm. In room and low temperature photoluminescence measurements of the as grown and RTA treated film, donor acceptor pair emission and exciton bound to acceptor recombination at 3.25 and 3.357 eV, respectively, were observed.     

Effects of annealing ambience on ZnO:N films grown by MOCVD and the p-type doping mechanism of ZnO:N films investigated by XANES

ZnO:N thin films were deposited on sapphire substrate by metal organic chemical vapor deposition with NH₃ as N-doping sources. The reproducible p-type ZnO:N film with hole concentration of ∼10¹⁷ cm⁻³ was successfully achieved by subsequent in situ thermal annealing in N₂O plasma protective ambient, while only weak p-type ZnO:N film with remarkably lower hole concentration of ∼10¹⁵ cm⁻³ was obtained by annealing in O₂ ambient. To understand the mechanism of the p-type doping behavior of ZnO:N film, X-ray photoelectron spectroscopy (XPS) and soft X-ray absorption near-edge spectroscopy (XANES) measurements have been applied to investigate the local electronic structure and chemical states of nitrogen atoms in ZnO:N films.     

Structural, optical and electrical properties of Al-N codoped ZnO films by RF-assisted MOCVD method

N-doped ZnO films were produced using N₂ as N source by metal-organic chemical vapor deposition (MOCVD) system which has been improved with radio-frequency (RF)-assisted equipments. The data of secondary ion mass spectroscopy (SIMS) indicate that the concentration of N in N-doped ZnO films is around 5 × 10²⁰ cm⁻³, implying that sufficient incorporation of N into ZnO can be obtained by RF-assisted equipment. On this basis, the structural, optical and electrical properties of Al-N codoped ZnO films were studied. Then, the effect of RF power on crystal quality, surface morphologies, optical properties was analyzed using X-ray diffraction, atomic force microscopy and photo-luminescence methods. The results illustrate that the RF plasma is the key factor for the improvement of crystal quality. Then the observation of A⁰X recombination associated with N_O acceptor in low-temperature PL spectrum proved that some N atoms have occupied the positions of O atoms in ZnO films. Hall measurements shown that p-type ZnO film deposited on quartz glasses was obtained when RF power was 150 W for the Al-N codoped ZnO films, while the resistivity of N-doped ZnO films was rather high. Compared with the Al-doped ZnO film, the obviously increased resistivity of codoped films indicates that the formation of N_O acceptors compensate some donors in ZnO films effectively.     

Electrical properties and Raman scattering investigation of Ag doped ZnO thin films

Ag-doped ZnO thin films were deposited on quartz glass substrates by a radio-frequency (RF) magnetron sputtering technique at room temperature (RT). The influence of Ag doping content on the electrical and Raman scattering properties of ZnO films were systematically investigated by Hall measurement system and Raman scattering spectrum. Two additional local vibrational modes (LVMs) at 230.0 and 394.5 cm^?1 induced by Ag dopant in ZnO:Ag films were observed by Raman analyses at RT, corresponding to Ag atoms located at O sites (LV M_Zn?Ag) and Zn sites (LV M_Ag?O) in ZnO lattice. Moreover, we further studied the effect of donor Ag_O and acceptor Ag_Zn defects on the electrical properties of ZnO:Ag films. The results indicate that O-rich condition is preferred to suppress the formation of Ag_O defects and enhance Ag_Zn defects. The p-type ZnO:Ag film was achieved by properly optimizing the annealing conditions under O-rich condition.     

Room-temperature ferromagnetism in N+-implanted ZnO:Mn thin films

Mn–N co-doped ZnO films with wurtzite structure were fabricated by RF magnetron sputtering together with the ion-implantation technique. Then a post-annealing at 650 °C for 10 min in a N₂ atmosphere was performed to activate the implanted N⁺ ions and recover the crystal quality, and a p-type ZnO:Mn–N film with a hole concentration of about 2.1×10¹⁶ cm^?3 was obtained. It is found that the Mn mono-doped ZnO film only exhibits paramagnetic behavior, while after N⁺-implantation, it shows ferromagnetism at 300 K, and the magnetization of the ZnO:Mn–N films can be further enhanced by thermal annealing due to the activation of the N acceptors. Our experimental results confirm that the codoping N acceptors are favorable for ferromagnetic ordering of Mn²⁺ ions in ZnO, which is consistent with the recent theoretical calculations.     

离子束增强沉积制备p型氧化锌薄膜及其机理研究

采用离子束增强沉积方法在Si和SiO₂/Si衬底上制备In-N共掺杂ZnO薄膜(INZO)，溅射靶是用ZnO和2 atm% In₂O₃粉体均匀混合并压制而成，在氩离子溅射ZnO靶的同时，氮、氩混合离子束垂直注入沉积的薄膜.实验结果显示INZO薄膜具有(002)的择优取向，并且为p型导电，电阻率最低为0.9Ωcm.薄膜在氮气、氧气气氛下退火，对薄膜的结构和电学特性与成膜和退火条件的关系进行了分析. 关键词： 氧化锌薄膜 p型掺杂 离子束增强沉积     

Ag掺杂p型ZnO薄膜及其光电性能研究

采用超声喷雾热分解法在石英衬底上以醋酸锌水溶液为前驱体,以硝酸银水溶液为Ag掺杂源生长了Ag掺杂ZnO(ZnO：Ag)薄膜.研究了衬底温度对所得ZnO：Ag薄膜的晶体结构、电学和光学性质的影响规律.所得ZnO：Ag薄膜结构良好,在室温光致发光谱中检测到很强的近带边紫外发光峰,透射光谱中观测到非常陡峭的紫外吸收截止边和较高的可见光区透过率,表明薄膜具有较高的晶体质量与较好的光学特性.霍尔效应测试表明,在500℃下获得了p型导电的ZnO：Ag薄膜,载流子浓度为5.30×10¹⁵cm关键词： ZnO：Ag薄膜 p型掺杂 超声喷雾热分解 霍尔效应     

The effects of thermal annealing in NH3 -ambient on the p-type ZnO films

Thermal annealing in NH₃-ambient was carried out to form p-type ZnO films. The properties were examined by X-ray diffraction (XRD), Hall-effect measurement, photoluminescence (PL), and secondary ion mass spectrometry (SIMS). Electron concentrations in ZnO films were in the range of 10¹⁵–10¹⁷/cm³ with thermal annealing in NH₃-ambient. The activation thermal annealing process was needed at 800 C under N₂-ambient to obtain p-type ZnO. The electrical properties of the p-type ZnO showed a hole concentration of 1.06×10¹⁶/cm³, a mobility of 15.8 cm²/V s, and a resistivity of 40.18 Ω cm. The N-doped ZnO films showed a strong photoluminescence peak at 3.306 eV at 13 K, which is closely related to neutral acceptor bound excitons of the p-type ZnO. The incorporation of nitrogen was confirmed in the SIMS spectra.